Why Are Monarch Butterflies Disappearing

The Washington Post recently ran a very insightful article about the dramatic decline in the monarch butterfly population over recent years. Each year, the butterflies migrate to Mexico, where they spend the winter before returning to various parts of the United States. Last year, there were about 50 million butterflies — this year, the number could be half that. So what is behind the distributing trend? Journalist Brad Plummer talks with Lincoln Brower, a professor of biology at Sweet Briar College, to get the full story. Read the article…

Source: Brower et. al 2012 updated with data from the author for the past two years